Telephone line pulsing device



29, 5- A. G. MILASUS 2,410,173

TELEPHONE L INE PULSING DEVICE Filed Nov. 9; 1945 Patented Oct. 29, 1946 UNITED STATES PATENT OFFICE TELEPHONE LINE PULSING DEVICE Aloysius G. Milasus, Roselle, N. J.

Application November 9, 1945, SerialNo. 627,731

Claims. 1

This invention relates to telephone equipment and more particularly to a line pulsing device for operating automatic office equipment of a telephone system.

When a telephone subscribers station is com nected, to automatic ofiice equipment, such as in the widely used dial system, some means. must be included in the subscribers equipment for opening and closing the line circuit rapidly a predetermined number of times. In the well-known dial device in current widespread use, a finger plate is provided with holes in it. When the finger is placed in a hole and-the dial rotated to a finger stop a helical spring is wound up. When the dial is released, the spring. causes it to rotate to its normal position, operating a ratchet as it turns; this causes a pair of contacts to open and close the circuit the number of times indicated by the number dialed.

A main object of the present invention is to provide a novel and improved circuit pulsing means for. the above purpose of very much simplified structure, as. compared with the conventional dial device, and being effective to furnish the required line pulses in a much shorter time than the dial device.

A further object of the invention is to provide an improved telephone line pulsing structure which is very rapid and reliable in operation and is very economical to manufacture.

Further objects and advantages of the inventiOn will appear from the following description and claims, and from the accompanying drawing, wherein the figure is a schematic diagram of a telephone line pulsing device constructed and arranged in accordance with this invention.

Referring to the drawing, II and I2 designate conductors respectively connected to the telephone line terminals, said conductors being adapted to establish a circuit for furnishing a line pulse each time they are connected together. Mounted in the subscribers equipment is a stationary bar member I3 formed with alternating non-conducting portions I4 and conducting portions I5, there being six non-conducting segments I4 and five conducting segments I5. Conductor I2 is electrically connected to each of the conducting segments I5.

Mounted in the subscribers equipment with its axis extending parallel to bar member I3 is a solenoid I6 having an axial, movable plunger member I! positioned therein. The outer end of plunger member I! carries an arm II! which is provided with a contact roller I9 adapted to engage bar I3. Plunger member I! is provided with a collar 29 and a coil spring M is positioned between collar and solenoid Iii which biases plunger member IT to a position wherein contact roller I9 engages the outermost non-conducting segment I4 of bar member I3. Conductor II is electrically connected to arm I9. In the normal deenergized condition of solenoid i6 spring 2| thus maintains conductors II and I2 disconnected.

Solenoid I6 is provided with an energizing winding 22', one end of which is connected through a retarding inductor 23 to one terminal of the secondary winding of a step-down transformer 24-. The other terminal of the transformer: secondary winding is connected to a buss bar 25hf-Wlllgfl0illle0ted' thereto the movable contact arms of ten switch members designated as S--I to SIll; respectively, which may be of the normally open spring-biased push-button type.

The end of winding 22 is connected to the stationary contact of switch S-IO.

Winding 22' is progressively tapped at nine points along its length and the taps are respectively connected through the respective compensating resistors R,I' to R,9 t0 the respective stationary contacts of switch members S-I to 8-9. 1

The primary winding of transformer 24 is connected to an appropriate source of alternating current, such as to the volt house current line.

Winding 22 includes a sufiicient number of turns and has a resistance'such that when switch SI0 is closed a magnetomotive force is developed, in solenoid I6 which is efiective to draw plunger member IT rearwardly against spring ZI to a position wherein contact roller member I9 engages the rearmost non-conducting portion l4. In so doing, roller member I9 successively engages five conducting segments I5, producing five pulses in the telephone line. When switch SIll is released, plunger I'I' returns to its normal position, producing five more pulses.

Resistance R-9 is of such a value that in conjunction with the number of turns of winding 22 included at its top and with the resistance of the included turns a magnetomotive force is developed in solenoid I6 when switch S!! is closed which is sufficient to draw plunger member I! rearwardly against spring 2| to a position wherein roller member I9 engages the rearmost conducting segment I5 of bar member l3. In so doing, roller member I9 causes five pulses to be delivered to the telephone line. When switch S-9 is released, plunger II returns to normal position, producing four more pulses.

Resistor R8 is of such a value that the plunger will be drawn rearwardly when switch S8 is closed to a position wherein roller member l9 engages the fifth non-conducting segment I4, producing four pulses on its rearward movement, and producing four more pulses when switch S--8 is opened to release plunger ll. The remaining resistors are similarly graduated in value so that the closing and opening of their associated switch members provides selective movement of plunger member I! to selectively produce the desired number of line pulses. t is thus possible to selectively obtain from one to ten pulses in the line by momentarily closing a correspondingly numbered switch member.

Retarding inductor 23 is provided to slightly delay the building up and decay of magnetomotive force in solenoid l6 solas to dampen the motion of plunger I! slightly and to assure substantial contact of roller member IS with conductor segments l5 as said roller member progresses along bar member l3. Where faster operation of the pulsing device is required, retard ing inductor 23 may be omitted.

Whereas in the conventional dial system the forward rotation of the dial merely winds up its spring and produces no pulses, in the device of the present invention pulses are produced both for forward and rearward travel of plunger ll, thus pulsing the line in a much shorter time than that required to obtain the same result in the dial system. The operation of the present invention is also much simpler in that the subscriber merely momentarily presses a push-button corresponding to the digit to be dialed instead of inserting his finger in a finger hole and rotating a dial member to a finger stop.

The values of resistance of resistors R| to R9 will be graduated, the value for R-l being greater than for R-2, the value for R2 being greater than for R-3, etc. The values of these resistors may be calculated from the expression:

where M is the required magnetomotive force, N is the number of included turns, and I is the current required. The value of a resistor is then given by E -12. (2) where E is the applied voltage and R5 is the resistance of the included turns.

While a specific embodiment of a telephone line pulsing device has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore it is intended that no limitations be placed on the invention other than as defined by the scope of the appended claims.

What is claimed is:

1. A telephone line pulsing device comprising a bar member having a plurality of linearly spaced contact portions, a solenoid arranged with its axis parallel with said bar member, a movable plunger axially positioned in said solenoid, the outer end of said plunger carrying an element in movable engagement with said bar member, a retarding inductor connected in the energizing circuit of said solenoid, a first line conductor connected to said contact portions, a second line conductor connected to said plunger-carried ele ment, and means for momentarily moving said plunger inwardly of said solenoid a predetermined distance.

2. The structure of claim 1, and wherein said means comprises a tapped connection to said solenoid and a resistor in series with said tapped connection.

3. The structure of claim 1, and wherein said plunger is spring-biased to a normal position wherein the plunger-carried contact element engages a non-conducting portion of said bar member, and wherein said means comprises a plurality of tapped connections to said solenoid, each connection having a resistor in series therewith, the resistors being of diflferent values.

4. A telephone line pulsing device comprising a bar member having alternating conducting and non-conducting portions, a solenoid arranged with its axis parallel with said bar member, a movable plunger axially positioned in said solenoid, the outer end of said plunger carrying a roller element in. rolling contact with said bar member, a first line conductor connected to said conducting portions, a second line conductor connected to said roller element, a spring-biasing said plunger to an outer position wherein the roller element engages a non-conducting portion of said bar member, a plurality of tapped connections to said solenoid, each connection having a resistor in series therewith, the resistors being graduated in value and being of such values that when the energizing circuit for the solenoid includes one of said tapped connections the plunger will be moved inwardly a predetermined distance, and a retarding inductor included in the energizing circuit for the solenoid.

5. The structure of claim 4. and wherein there are nine tapped connections, each tapped connection corresponding to a different predetermined distance of inward movement of said plunger.

ALOYSIUS G. MILASUS. 

